Over the past ten years, the climate-change-induced events that
have had the greatest impact on the metro system include
cloudbursts, storm, lightning strikes and storm surges. These types
of weather event are at the core of Metroselskabet's climate
efforts. Cloudbursts and storms often tend to be very localised and
its difficult to predict the force of these events because they can
vary considerably within only a short distance. Risk analyses of
cloudbursts and storms therefore include the entire metro system,
and a specific assessment is required for each individual
installation.
The layout of streets around the underground stations is designed
so that the stormwater will run away from the stairwells, and
therefore, in some places, you have to walk up a few steps before
descending the stairs to the underground station. Another example
is places where the metro runs from stretches above ground down
into the tunnels. A strong drainage grate has been established
across the tracks on the way down into the tunnels where stormwater
from above ground is accumulated and pumped away before reaching
the tunnels. Should the water reach the tunnels despite the grates,
it will be led to retention wells and pump wells. The underground
stations have also been secured against backflow from the city's
sewer network. In the event of very critical situations, this has
also been taken into consideration
At some stations (here Kongens Nytorv), an extra step has
been established in front of the metro access way.
On stretches where the metro system is directly linked to other
infrastructure, storm-surge gates have been established. This is
the case at Frederiksberg, Nørreport and Kongens Nytorv stations,
because at these stations there is direct underground access to
shopping centres or the electrified railways of Greater Copenhagen.
Furthermore, technicians' rooms have been fitted with watertight
outer doors at several stations assessed to be at risk of flooding.
Some technicians' rooms even have extra 30cm-high doorsteps. All
electrical and mechanical installations are watertight.
Along the stretches above ground, drains have been established
along the tracks leading water out into the local sewer system.
Furthermore, trees etc. have been removed which would otherwise
pose a danger to the tracks on the open stretches. On the basis of
flood-risk analyses, gabion walls have been built along exposed
above-ground stretches, such as on Eastern Amager. A gabion wall is
a wall made from a cage filled with rocks; a technique that is used
in coastal defences and breakwaters.